@article {3672,
	title = {Impact of casein- versus whey-based lamb milk replacers on growth and health of artificially reared lambs},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {81},
	year = {2021},
	month = {01/2022},
	pages = {22-28},
	address = {Online},
	abstract = {High cost of milk proteins has driven development of cheaper whey-based milk replacer (WBMR) as an alternative to skim-milk (casein)-based milk-replacer (CBMR) for artificial-rearing of young ruminants. This study compared growth, antibiotic/anti-inflammatory use and mortality in lambs reared on either WBMR (n=138) or CBMR (n=151) in the first three weeks of rearing at commercial scale. There was a diet x rank interaction (P=0.001) whereby CBMR-fed single/twin and triplet/quad lambs had the highest average daily gain (ADG) independent of birth-rank (362 vs. 358 g/d respectively, SED=16.7) compared to WBMR-fed lambs where higher ADG was observed in triplet/quad compared to single/twin lambs (275 vs. 213 g/d respectively, SED=16.7). Males tended to have higher ADG than females (311 vs. 294, SED=9.7 g/d, P=0.064). Overall, there was a tendency for greater mortality (11\% vs. 4\%; P=0.055), and overall incidence rate (N/100 animal weeks) for use of antibiotics (4.43 vs. 1.27; P=0.073) and anti-inflammatories (4.59 vs. 1.59; P=0.099) in WBMR- than CBMR-fed lambs. These results highlight that CBMR under an ad-libitum milk-feeding regime supports greater ADG independent of birth-rank and reduces the incidence of disease in the first three weeks of life compared to WBMR. Furthermore, WBMR under an ad-libitum milk-feeding regime results in lower ADG of single/twin-born lambs compared to their triplet/quad counterparts.

Keywords: lambs; artificial rearing; milk replacer; composition; growth; health; mortality},
	issn = {1176-5283},
	author = {McCoard SA and Ryrie J and MacDonald T and Hea S-Y and Pacheco D and Stevens D}
}
@article {3672,
	title = {The impact of different management systems on behaviour and milk production of dairy ewes in different stages of lactation; a case study},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {78},
	year = {2018},
	month = {07/2018},
	pages = {116-121},
	address = {Lincoln},
	abstract = {Comparisons of New Zealand dairy sheep farm systems are currently lacking. The aim of this preliminary study was to evaluate
the effects of different management systems on the behaviour and milk production of East Friesian cross-bred sheep at different
stages of lactation. Two study groups were evaluated. In study group 1, a mob of 479 mixed-age, mid-lactation ewes were housed
24 h/day, and a separate mob of 473 mixed-age, mid-lactation ewes were managed in a hybrid system (housed between morning
and afternoon milkings; grazed lucerne overnight). Both received a total mixed ration (TMR) indoors. In study group 2, a mob of
604 mixed-age, late-lactation ewes grazed pasture 24 h/day, and a separate mob of 452 mixed-age late-lactation ewes were in a
hybrid system, grazing pasture overnight. For both study groups, individual milk yield, walking distance, lying time, live weight
(LW), and body condition score (BCS) were recorded. All sheep gained BCS and LW except fully grazed late-lactation ewes. For
study group 1, fully housed ewes in mid-lactation lay down less during the day, but more overnight compared to those in the hybrid
system, likely due to the latter grazing overnight. Lying bout times were similar between groups, while milk yield was 29\% less
in housed ewes compared to the hybrid ewes. For study group 2, grazing ewes in late-lactation lay down more, had longer lying
bouts, and walked further daily than those in the hybrid system, but both late-lactation treatment groups had similar milk yields.
In summary, the hybrid management system seems to improve milk yield in mid-lactation compared to the fully housed system,
whereas there was no difference between the hybrid and fully grazed systems in late-lactation. Lying behaviour and walking
distances (group 2 only) differed among different systems, however, it is unclear what this means in terms of animal welfare, and
warrants further investigation.},
	issn = {1176-5283},
	author = {Bliss AE and Chylinski C and Luo D and Sch{\"u}tz KE and Lowe K and Peterson SW and Stevens D and MacDonald T and McCoard SA}
}
@conference {3672,
	title = {Impact of early weaning on rumen fermentation profiles of artificially reared lambs},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {77},
	year = {2017},
	month = {06/2017},
	pages = {49-54},
	address = {Rotorua},
	abstract = {This study investigated the impact of weaning age on rumen fermentation profiles in lambs. Mixed-sex lambs (n=32) were ran-domly allocated to one of two weaning groups: early-weaning (4wk) and control (6wk). Milk replacer (24\% CP and 25\% fat, DM basis) was offered at 20\% of initial body weight. Lambs were weaned at either four or six weeks after commencement of the trial using a three-week step-down procedure, initiated at the start of week 2 (early weaned group) or week 4 (control group). Lambs were individually penned indoors and concentrate and chopped meadow hay were offered ad libitum and individual feed intakes recorded until week six. At the end of week six, lambs were moved onto a ryegrass-based pasture and transitioned to an all pasture diet by week ten. Rumen contents were collected at slaughter, half of the lambs from each group at week four and sixteen, to de-termine rumen pH, and short chain fatty acid (SCFA) and ammonia concentrations. Ammonia concentrations were 132\% greater (P<0.05) in early weaned than control lambs at week four, but did not differ at week sixteen. Weaning age did not affect ruminal pH and SCFA total concentrations and proportions at week four or sixteen. The results suggest that ruminal fermentation can be established in lambs weaned off milk by four weeks using a step-down weaning method.},
	issn = {1176-5283},
	author = {Cristobal-Carballo O and Khan MA and Knol FW and Lewis SJ and Stevens D and McCoard SA}
}
@conference {3672,
	title = {The lying behaviour of non-lactating, pregnant dairy cows wintered in a loose-housed barn on woodchip bedding material},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {75},
	year = {2015},
	month = {07/2015},
	pages = {24-28},
	address = {Dunedin},
	abstract = { Winter represents an important time for dairy herds in the southern South Island of New Zealand. In an attempt to address poor
performance in forage crop-based wintering systems, farmers are increasingly using off-paddock methods of wintering, such as
housing their cows in barns. The aims of this study were to monitor the lying behaviour of cows wintered in a loose-housed barn
with woodchip bedding during three separate seven day periods to determine (i) if recommended lying times were being met, and
(ii) if bedding moisture content could be used as a predictor of lying time. Twenty-one non-lactating dairy cows were selected,
based on age, body condition score and stage of pregnancy, from a housed herd of 90 mixed-age cows. Lying and standing
movements were recorded at thirty second intervals using an electronic movement data logger attached to the ankle of each cow.
Monitoring in Period 1 commenced four days after the cows entered the barn for wintering in early June; Period 2 occurred in
early July, just prior to the removal and replacement of bedding material, and Period 3 occurred in mid-July when cows were again
on fresh bedding material. Average daily lying times were two hours longer during Periods 1 and 3, when barn material was fresh
(10.7 and 10.5 h/day, respectively), than when soiled during Period 2 (8.4 h/day). The difference in lying behaviour was due to a
difference in the number of lying bouts: cows had fewer lying bouts during Period 2 (6.1 per day) than Periods 1 \& 3 (7.4 and 7.9
per day, respectively). The average moisture content of the bedding was 60.7, 68.4 and 64 .3 \% for Periods 1, 2 and 3, respectively.
Bedding moisture content per se did not appear to be a good predictor of lying time, suggesting other factors such as bedding temperature and cleanliness and stage of pregnancy were influencing lying behaviour. These results are discussed in relation to bedding surface management and the welfare of housed dairy cows.},
	issn = {1176-5283},
	author = {Davison LJ and Dalley DE and Chrystal J and Monaghan R and Laurenson S and Stevens D and Wall A and Pigou J and Gorton A}
}
